DNAkorjausprosesseihin

DNAkorjausprosesseihin, tai DNA repair mechanisms in English, refers to the set of biological processes that identify and repair damage to DNA molecules. DNA is constantly exposed to various damaging agents, both from internal metabolic processes and external environmental factors such as radiation and chemicals. If left unrepaired, DNA damage can lead to mutations, which can have severe consequences for cell function, organismal health, and evolution.

There are several major DNA repair pathways, each specialized to handle different types of DNA lesions. Base excision repair (BER) corrects damage to single bases, such as oxidation or deamination. Nucleotide excision repair (NER) removes bulky, helix-distorting lesions, like those caused by UV radiation. Mismatch repair (MMR) corrects errors that occur during DNA replication, such as insertion or deletion of nucleotides. Double-strand break repair (DSBR) addresses breaks in both strands of the DNA helix, with two main pathways: non-homologous end joining (NHEJ) and homologous recombination (HR). NHEJ is a rapid but error-prone mechanism, while HR is more accurate but requires a homologous template.

These repair systems are essential for maintaining genomic integrity. Defects in DNA repair mechanisms are linked to a wide range of diseases, including cancer, neurodegenerative disorders, and premature aging syndromes. The study of DNA repair is crucial for understanding fundamental biological processes and for developing therapeutic strategies for diseases caused by DNA damage.